modify C# 2008 desktop application

Question

In an existing C# 2008 windows application I am trying to decide how to  use the existing application without rewriting it. Currently there is a 'driver C# 2008 windows' program that calls the 'main C# 2008 desktop' application to perform various caLLS to a third parfty web service.

Now I would like to use the 'main C# 2008 desktop' application to be run by users. The users would enter the required paramters in a desktop screen and/or possibly a dos popup window. The application would know who is running the program by the paramters that are passed to the application.

Thus my question is, can a desktop screen and/or a dos popup window show up when users click on the executable? The default would be for the no desktop window to show up when the program is called by the 'driver C# 2008 windows' program.

Thus can you show me code and/or point me to urls that would show me how to accomplish this goal? If my goal not realistic, can you suggest other ways that I can accomplish the add on goal I am trying to acheive?